Silberwise's post here (http://www.steelbeasts.org/showthread.php?6079-Grafikproblem) showed to me that TS3Overlay could work with Steel Beasts, I just didn't know how. After some trial and error with the latest TS3Overlay version 3.7.10, I got it working with Steel Beasts.
Here's how:
Go to Plugins and enable TS3Overlay.
Click Settings.
Select the SBPROPECM.EXE profile from the drop down profile menu.
Go to the Extended tab.
Check the box "Use ID3DDevice::Present hook (instead of ID3DDevice::EndScene)".
Enjoy TS3Overlay working with Steel Beasts in full screen.
